i have just purchased some ver4 sti heads for my 1993 wrx, what else do i need to fit this so i have every thing ready for the change over, any advice would be appriecated. cheers steve

 

Keep all your 1993 stuff (except the heads, obviously).

Your existing 1993 inlet manifold bolts straight onto the v4 heads, so can keep all the ancilliaries, for the easiest, pain-free swap.

Speak to API David re HG thickness to use. I still think it'll be a 1.6mm one though...